South Carolina Transportation Technology Transfer Service Spring 2002 Quarterly

Proper Drainage Reduces Roadway Problems

Editor’s Note: This article is reprinted, with permission, from the Spring 2002 Nevada Milepost, the newsletter of the Nevada Technology Transfer Center.

Inadequate drainage not only causes creasing traffic volumes. have shoulders that will convey the driving problems, it also causes design runoff without encroaching h The intensity of rainfall may sig- roads to deteriorate rapidly. on the traffic lanes. nificantly affect the selection of Pavement drainage requires consid- design frequency and spread. The recommended design fre- eration of surface drainage, gutter quency for depressed sections and Risks associated with the spread flow and inlet capacity. The design underpasses where ponded water of water on pavements may be of these elements depends on storm can be removed only through the less in arid areas subject to high frequency and the allowable spread storm drainage system is a 50-year intensity thunderstorms than in of storm water on the pavement sur- frequency event. areas accustomed to frequent but face. less intense storms. Design Frequency and Spread h Cost considerations make it nec- (Continued on page 3) essary to formulate a rational de- h The classification of the highway sign criteria. is a good starting point in the se- Volume 13 Number 1 lection process because it defines The elevation of the highway and In This Issue… the public's expectations regard- surrounding terrain is an additional ing water on the pavement sur- consideration when water can be Proper Drainage Reduces Roadway face. drained only through a storm drain- Problems age system, as in underpasses and h Ponding on traffic lanes of high- Page 1 depressed sections. speed, high-volume highways is T3S Welcomes New Staff Member contrary to the public's expecta- Spread on traffic lanes can be toler- SE Local Roads Conference tions. Therefore, the risks of acci- ated to greater widths where traffic Page 2 dents and the costs of traffic de- volumes and speeds are low. lays are high. Spreads of one-half of a traffic lane Videos and Publications Page 4 or more usually are considered a h Design speed is important to the minimum type design for low- selection of design criteria. At Culvert Repair volume local roads. Page 5 speeds greater than 40 mph, wa- ter on the pavement can cause The selection of design criteria for Health and Safety Issues hydroplaning. intermediate types of facilities may Page 6 be the most difficult. For example, h Projected costs of traffic delays some arterials with relatively high Publication and Video Order Form and accidents increase with in- traffic volumes and speeds may not Page 7

The LTAP Center for South Carolina Page 1 South Carolina Transportation Technology Transfer Service Spring 2002 3 T S Welcomes New Staff Member

We would like to welcome Debbie aison with all T3S customers to Lipscomb to the T3S staff. Debbie ensure that we are meeting their joined us in February as Program needs. She will now be responsi- Coordinator. You will have the op- ble for developing our future portunity to get to know her as you workshop topics and schedules. register for conferences and work- Sandi will also head up our ma- shops as well as meet her at work- jor conference activities, includ- shop locations throughout the state. ing the SE Local Roads Confer- Debbie will also be managing the ence later this year and the SC video and publications library for State Highway Conference each T3S so you will have many oppor- year. She also will have primary tunities to talk with her and wel- responsibility for additional du- come her to the program. 888.414.3069. She can also be ties that T3S has taken on to as- reached at her direct e–mail ad- She is a South Carolina native, but sist the SCDOT Research Unit. dress, [email protected] just recently returned to the upstate. (which is not reflective of her per- Sandi will continue to be in- Her employment history includes sonality!), or at volved with seminars as time an area in the transportation indus- [email protected]. permits, and is only a phone call try as a Petty Officer in the United away. She can be reached di- States Coast Guard, stationed in So, Where’s Sandi? rectly at her new phone number, California. We are excited about 864.656.6141, or via the T3S having Debbie “on board” with Sandi is still here but has been pro- toll–free number, 888.414.3069. T3S. moted to Program Manager for Her e–mail address is T3S. In this position Sandi will You can reach Debbie at [email protected]. have primary responsibility for li- 864.656.1456 or toll free at

T3S Will Host SE Local Roads Conference Sept 22–24 at the Wyndham Myrtle Beach Resort

The 2002 conference will be hosted by your SC LTAP Center (T 3S) and is a collaboration of the Federal Highway Administration and the southeastern LTAP Centers. More infor- mation regarding the Conference will be available at the conference web site that can be reached via the T3S web site: www.ce.clemson.edu/t3s. The details of the conference are being finalized and additional information will be published at the web site as it becomes available. The Wyndham Resort is located directly on the beach, and we have an excellent conference room rate of $65 per night, plus tax and a small resort fee. While the agenda is not yet finalized, the Conference will include a wide array of presenta- tions related to local roads topics that will be of interest to city, county, and DOT person- nel, as well as local elected officials and private sector employees. The conference will also include a vendor exhibit area, as well as a welcome reception, continental breakfast each day, and a luncheon. A golf outing is also planned for the 22nd. Please visit our web site often for updated information. This is an excellent opportunity for South Carolina municipal and county roads personnel to obtain up–to–date in- formation on a number of important topics relating to local roads. Please put these dates on your calendars and plan to attend this important conference.

Page 2 The LTAP Center for South Carolina South Carolina Transportation Technology Transfer Service Spring 2002

in the AASHTO Policy on Geo- cross slope should be limited to 4 (Continued from page 1) metric Design include three gen- percent. Check Storm and Spread eral guidelines. Curb and gutter A check storm should be used any 1. A minimum longitudinal gradi- time runoff could cause unaccept- ent is more important for a Normally curbs are used at the able flooding during less frequent curbed than for an uncurbed outside edge of pavements for storms. Inlets also should always be pavement because water is con- low-speed highways, and in some evaluated for a check storm when a strained by the curb. Flat gradi- instances, adjacent to shoulders series of inlets terminates at a sag ents on uncurbed pavements can on moderate to high-speed high- vertical curve where ponding to lead to a spread problem if vege- ways. They serve the following hazardous depths could occur. tation is allowed to build up purposes: Criteria for spread during the check along the pavement edge. h Contain the surface runoff storm are: 1) one lane open to traf- 2. Desirable gutter grades should within the roadway and away fic during the check storm, and 2) not be less than 0.5 percent for from adjacent properties one lane free of water during the curbed pavements with an abso- h Prevent erosion on fill slopes. check storm. These criteria differ lute minimum of 0.3 percent. substantively, but each sets a stan- Minimum grades can be main- h Provide pavement delineation. dard by which the design can be tained in very flat terrain by us- h Enable the orderly development evaluated. ing a rolling profile or by warp- of property next to the road. ing the cross slope to achieve Hydroplaning rolling gutter profiles. Gutters formed in combination with curbs are available in 12- The hydroplaning potential of a 3. To provide adequate drainage in through 39-inch widths. Gutter roadway surface can be reduced. sag vertical curves, a minimum cross slopes may be the same as h Design highway geometries to slope of 0.3 percent should be that of pavement or may be de- reduce drainage path lengths of maintained within 50 feet of the signed with a steeper cross slope, water flowing over the pavement. low point of the curve. usually 1 inch per foot steeper This prevents flow build up. than the shoulder or parking lane. Cross/Transverse Slope AASHTO geometric guidelines h An increase of pavement surface state that an 8 percent slope is a texture, such as grooving or Cross slopes of 2 percent have lit- common maximum cross slope. grinding, will increase the drain- tle effect on driver effort in steer- age capacity at the pavement ing or on friction demand for vehi- Channels interface. cle stability. In areas of intense rainfall, a somewhat steeper cross Roadside channels are commonly h The use of open-graded asphalt slope of 2.5 percent may be used to used with uncurbed roadway sec- pavements greatly reduce the hy- facilitate drainage. tions to convey runoff from the droplaning potential of the road- highway pavement and from areas way surface because this forces On multi-lane highways where that drain toward the highway. water through the pavement un- three lanes or more are sloped in Due to right-of-way limitations, der the tire. the same direction, it is desirable to counter the resulting increase in roadside channels cannot be used h Drainage structures to capture the flow depth by increasing the cross on most urban arterials. They can flow of water over the pavement slope of the outermost lanes. be used in cut sections and other will reduce the thickness of the locations where sufficient right- film of water and reduce hydro- The two lanes adjacent to the of-way is available and driveways planing potential. crown line should be pitched at the or intersections are infrequent. normal slope, and successive lane To prevent drainage from the me- Design guidance pairs or outward portions should be increased by about 0.5 percent to 1 dians from running across the The recommended minimum values percent. The maximum pavement (Continued on page 4) of roadway longitudinal slope given

The LTAP Center for South Carolina Page 3 South Carolina Transportation Technology Transfer Service Spring 2002

(Continued from page 3) h Hydroplaning often occurs at Additionally, runoff from bridge travel lanes, slope medians and in- shallower depths on bridges due decks should be collected immedi- side shoulders to a center swale. to the reduced surface. ately after it flows onto the subse- This design is particularly impor- quent roadway sections where lar- Bridge deck drainage is often less tant for high speed highways and ger grates and inlet structures can efficient than roadway sections be- for highways with more than two be used. cause cross slopes are flatter, para- lanes of traffic in each direction. pets collect large amounts of debris Median Barriers and drainage inlets or typical bridge Bridge Decks scuppers are less hydraulically effi- Slope the shoulder areas adjacent to Bridge deck drainage is similar to cient and more easily clogged by median barriers to the center to pre- that of curbed roadway sections. debris. vent drainage from running across Effective bridge deck drainage is the traveled pavement. Because of the difficulties in pro- important for the following reasons: viding for and maintaining adequate Where median barriers are used, h Deck structure and reinforcing deck drainage, gutter flow from and particularly on horizontal steel is susceptible to corrosion roadways should be intercepted be- curves with associated super eleva- from deicing salts. fore it reaches a bridge. For similar tions, it is necessary to provide inlets or slotted drains to collect the h Moisture on bridge decks freezes reasons, zero gradients and sag ver- water accumulated against the bar- before surface roadways. tical curves should be avoided on bridges. rier.

Publications and Video Tapes Available

Publications The publications described below be educated in standard trenching and are free to any individuals em- backfilling techniques before starting Maintenance of Signs and Sign ployed by any city or county gov- any construction project. This video Supports for Local Roads and ernment agency in South Carolina. details four valuable lessons for the Streets. FHWA. You can obtain a single free copy beginner. The areas of emphasis de- Retroreflective Sheeting Identifica- of some publications or borrow a a scribed are planning, trenching and tion Guide. FHWA. copy of one of the “for loan” publi- backfilling, managing a spoil pile, cations or videos and lifting with the backhoe. VISTA. Pavement Preservation Forum II: Investing in the Future. FHWA. Night Lights. Describes how bright, Videos Highway Infrastructure: Protecting reflective material on roadways and the Nation’s Investment. FHWA. It’s About Time—Traffic Signal traffic safety devices saves lives by Management Cost Effective Street improving the roadway in a variety of Computer Software Capacity. Demonstrates the impor- scenarios. ATSSA. Pedestrian/ Safety Resource. tance and benefits of maintaining op- FHWA. timized and current traffic signal tim- The Right Choice for Rebuilding ing plans, and investing resources in Roads–—Full Depth Recycling with traffic signal systems. FHWA. Cement. Defines the process of full Editor’s Note: the publications depth recycling. FDR rebuilds worn and videos shown here can be Tips from the Pros—Backhoe out asphalt by recycling the existing ordered by completing the form Loader. Backhoe operators need to roadway. Portland Cement Assoc. on page 7 and faxing it to us.

Page 4 The LTAP Center for South Carolina South Carolina Transportation Technology Transfer Service Spring 2002 Guide to Culvert Repair Editor’s Note: Reprinted, with permission, from the Spring 2002 Nevada Milepost, the newsletter of the Nevada Technology Transfer Center.

Poorly working culverts can cause crushed or plugged culvert that al- Inspect your culverts at least once flooding during heavy rains that lows water to back up in roadside a year. After the inspection priori- significantly damages roads and ditches will contribute to the dete- tize the repair and maintenance bridges. rioration of the road as the standing they need and schedule the work water prevents further drainage through spring, summer and fall. Even during normal wet weather a from the road base and subgrade.

Culvert Ends

What you observe What the reason may be How to fix it

Ditch is too steeply graded Line the inlet with stone Scouring or erosion Pipe is poorly located or aligned Realign the pipe at the inlet No headwalls Install headwalls Pipe is clogged Clean and flush the pipe

Pipe is sloped too much Build a stone splash pad Scouring erosion No endwalls or aprons Install endwalls or aprons at the outlet Pipe is too small Check size and replace with larger pipe

Inlet is too high Reset the pipe; match the inlet to the channel “Ponded” water bottom Ditch grade is too flat Regrade the ditch to maintain correct flow

Dented or crushed ends Vehicles or snowplows are hitting the ends Fix, mark and protect the pipe ends

Install a sleeve of PVC in the pipe, or replace Heavy corrosion Water flowing through the pipe is acidic the steel pipe with PVC, aluminum, or con- crete pipe

Pipe is incorrectly installed, causing water to Reinstall the pipe on suitable properly com- “Piping” around outlet flow along the outside surface of pipe pacted bedding. Install a head wall Inside Culvert Pipe isn’t sloped enough Reinstall the pipe at a slope of at least 1/4 inch per foot Sediment buildup Objects blocking the pipe to the culvert Remove the blockage. Install check dams up- stream of the culvert

Foundation material has settled or has low Reinstall the pipe on a suitable, properly com- Sagging bottom bearing capacity pacted bedding

Cover is inadequate Add cover Soil around pipe isn’t compacted sufficiently Reinstall pipe more deeply and use suitable, properly compacted bedding and backfill or Crushed top install multiple small pipes or a pipe with a different shape Traffic load is too great Replace pipe with a stronger one

Install a sleeve of PVC in the pipe with PVC, Heavy corrosion Water flowing through the pipe is acidic aluminum or concrete

The LTAP Center for South Carolina Page 5 South Carolina Transportation Technology Transfer Service Spring 2002 Apply Cold Packs Gasoline is Explosive

to a Strain Gasoline is so volatile that one gallon is equivalent to 14 sticks of dyna- When you strain a ligament or a mite in explosive force. Vapors from gasoline are very dangerous. They muscle, applying cold packs for are heavier than air and will flow invisibly along the ground. They will ig- the next 1 to 3 days is the best nite from a flame, spark, or static electricity, causing an explosion. treatment. Don't use heat. Hot ♦ Never use gasoline around a flame source such as matches, cigarettes, soaks or a heating pad may in- or pilot lights on stoves and water heaters. crease swelling and inflammation. ♦ Only use gasoline outdoors or in a well ventilated area. Use cold because: ♦ Fill the tanks of gasoline-powered equipment when engines are turned Cold reduces swelling and in- off and cold. flammation. Cells may be dam- ♦ Don’t carry gasoline in your . A fiery explosion can result if there is aged because swelling decreases a collision or if vapors escape. the oxygen supply to surround- ♦ If gasoline is spilled on clothing, remove it immediately. Place cloth- ing tissues. Cold applications ing outdoors for several days before washing and drying so that gaso- lower the metabolism within the line vapors can evaporate. (Clothes driers can catch fire if vapors are cells and allow the tissue to sur- not allowed to evaporate first, even if the clothing has been washed. vive a temporary lack of oxygen, ♦ Never store gasoline inside a building. according to the Mayo Clinic. ♦ Use only approved safety cans, which have flame arrestors and pressure This promotes the repair of cells release valves. and speeds healing. ♦ Keep gasoline locked up and away from children when not in use. Cold constricts blood vessels, which helps control bleeding within the injury. Home Safety Stressed Cold relieves pain and acts as a local anesthetic. The National Safety Council wants employers to put more emphasis on off-the-job safety. They Bruising usually stops within 1 to say that organizations must now think about the 3 days after an injury. To relieve safety of their people and their families in a muscle spasms and the pain of mi- broader context. Safety Council President Alan nor sprains and strains, it's best to McMillan reports that about 5,200 people died at apply cold for about 20 minutes at work in the year 2000, while nearly 52,000 died in the home and community a time every 4 to 6 hours for the and 43,500 died in motor vehicle crashes. During more difficult business first 1 or 2 days. Commercial cold times, it's even more important to improve safety away from work. One na- packs are safer than using ice. Pro- tionwide employer described in Safety & Health magazine reports that 34 longed exposure to ice can result in percent of the benefits it pays are injury related, and indirect costs of injuries frostbite. When should you use can be as much as two times the direct costs. What happens at home has a heat? Heat is better for chronic direct impact on what happens at work. When a person is injured at home, it pain or for muscle relaxation. It means time away from work. If a child is injured or sick, parents could miss could be helpful after the first 3 or work or the parents' thoughts may be with the child even if they are at work. 4 days.

Bumper snickers If you can’t change your mind, are you still sure you have one?

I is a college student Hire teenagers while they If you can read this, still know everything Caution, I drive like you do I’ve lost my trailer

Page 6 The LTAP Center for South Carolina South Carolina Transportation Technology Transfer Service Spring 2002 Information Request and Address Change Form

To order any of the publications, videos, or other materials listed in this or other issues of T 3S Quarterly, complete this form and mail it or fax it to Debbie Lipscomb at the address or phone number shown below.

Transportation Technology Transfer Service Phone: 864.656.1456 Civil Engineering Department Clemson University, Box 340911 Fax: 864.656.2670 Clemson, SC 29634-0911

Publications and Software Maintenance of Signs and Sign Supports for Local Roads and Streets Retroflective Sheeting Identification Guide Pavement Preservation Forum II: Investing in the Future Highway Infrastructure: Protecting the Nation’s Investment

Pedestrian/Bicycle Safety Resource

Videos It’s About Time—Traffic Signal Management Cost Effective Street Capacity Tips from the Pros—Backhoe Loader Night Lights The Right Choice for Rebuilding Roads—Full Depth Recycling with Cement

Other

Name: ______Title: ______ This is a new address Address: ______ Please add my name to your ______mailing list Phone ______Fax ______

Suggestions for Possible Future Workshop Topics

The LTAP Center for South Carolina Page 7 South Carolina Transportation Technology Transfer Service Spring 2002

T 3S Quarterly is published by the South Carolina Transporta- tion Technology Transfer Service (T 3S) for the benefit of county and municipal government agency personnel in SC. T3S, administered by the Clemson University Civil Engineer- ing Department, is the Local Technical Assistance Program (LTAP) center for SC. T 3S is part of a nation–wide network of LTAP centers established by the Federal Highway Administra- tion (FHWA) in cooperation with state transportation agencies. T3S is jointly funded by FHWA and the SCDOT. The views, opinions, and recommendations contained in the newsletter do not necessarily reflect the views of the FHWA or the SCDOT.

How to Contact Us SC Transportation Technology Transfer Service Civil Engineering Department Clemson University — Box 340911 Clemson, SC 29634–0911 Phone: 888-414-3069 Fax: 864-656-2670 e-mail: [email protected]

Director: Jim Burati 864-656-3315 Program Manager: Sandi Priddy 864-656-6141

Program Coordinator: Debbie Lipscomb 864-656-1456

Permit No. 10 10 No. Permit Clemson, SC 29634-0911 29634-0911 SC Clemson,

Box 340911 340911 Box Clemson, SC SC Clemson,

Clemson University University Clemson U.S. POSTAGE PAID PAID POSTAGE U.S.

Civil Engineering Department Department Engineering Civil Nonprofit Organization Organization Nonprofit Transportation Technology Transfer Service Service Transfer Technology Transportation

Page 8 The LTAP Center for South Carolina